The current state of the Newdow case on the Pledge

Factual Questions
1
  1. I read on google news that the SCOTUS will hear the case on March 24th. True?
  2. Approximitely when will the SCOTUS give its ruling? Within a year? A few months?
  3. Should the SCOTUS rule it unconstitutional, how long will it take before the changes take effect?
2

Depends on the wording of the opinion, sort of. An unconstitutionality ruling is generally effective immediately. However, SCOTUS may suspend its own ruling pending a Congressional redrafting.

3

Yes, oral argument is scheduled for March 24. It will start at about 11:00 AM, if you want to go.

Decisions by the Court are typically issued a few months after the argument, and except in exceedingly rare cases all cases which have been argued will be decided by the beginning of summer, which is the informal end of the term. (Technically, the Supreme Court term now lasts all year in case an emergency case comes up during the summer recess.) Outside of that, there is no specific timeline for opinions – they take as long as they take. Often the opinions delivered at the end of the term are the hardest or most contentious, as they’re the ones that have taken the most time and effort to put together.

–Cliffy